A four-year-old girl escaped injury in west Belfast when she picked up a pipe-bomb and brought it into her home.
The child discovered the device yesterday in the Springfield Road area, which runs along the peace-line.
The RUC said she carried the unexploded bomb into her house. Her mother immediately removed it to the front garden. British army bomb disposal experts later dealt with the device.
There have been some 50 pipe-bomb attacks by loyalists this year. The UDA has been blamed for most of them.
However, suspicion has grown of some involvement by the other mainstream loyalist paramilitary group, the UVF, after a bomb-making factory was discovered last weekend in a block of flats in north Belfast.
The haul in Mount Vernon included 11 pipe-bombs, home-made explosives and a substantial primed bomb consisting of 45lb of explosives packed into a fire extinguisher.
Mount Vernon is a UVF stronghold. The Progressive Unionist Party, the UVF's political wing, has admitted the bombs belonged to the paramilitary group. However, a party Assembly member, Mr Billy Hutchinson, yesterday said the devices were not intended for immediate use.
"The explosives that were found were not used in any of the pipe-bombings in and around north Belfast or across the province," he told BBC Radio Ulster.
"There have been some contradictions in what the police have said and what local people are saying. The UVF are carrying out a full inquiry."
Mr Hutchinson said he had been told the explosives were "moved around north Belfast" during the UVF-UDA feud last year. He condemned the decision to move the explosives to a heavily-populated area.
Meanwhile, the RUC is investigating a motive for the attempted murder of a leading loyalist in Ballymoney, Co Antrim. The 33-year-old man, who has PUP links, was shot and wounded as he left a house on Finvoy Road on Monday night.
Detectives have ruled out a sectarian motive and believe the shooting may be connected to inter-loyalist tensions. The victim was hit in the leg. His condition is said to be comfortable in hospital. The shooting was condemned by the DUP.